/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.runtime.io.network.metrics;

import org.apache.flink.runtime.io.network.partition.consumer.SingleInputGate;

import static org.apache.flink.util.Preconditions.checkNotNull;

/**
 * Gauge metric measuring the input buffers usage for {@link SingleInputGate}s under credit based mode.
 */
public class CreditBasedInputBuffersUsageGauge extends AbstractBuffersUsageGauge {

	private final FloatingBuffersUsageGauge floatingBuffersUsageGauge;
	private final ExclusiveBuffersUsageGauge exclusiveBuffersUsageGauge;

	public CreditBasedInputBuffersUsageGauge(
		FloatingBuffersUsageGauge floatingBuffersUsageGauge,
		ExclusiveBuffersUsageGauge exclusiveBuffersUsageGauge,
		SingleInputGate[] inputGates) {
		super(checkNotNull(inputGates));
		this.floatingBuffersUsageGauge = checkNotNull(floatingBuffersUsageGauge);
		this.exclusiveBuffersUsageGauge = checkNotNull(exclusiveBuffersUsageGauge);
	}

	@Override
	public int calculateUsedBuffers(SingleInputGate inputGate) {
		return floatingBuffersUsageGauge.calculateUsedBuffers(inputGate) + exclusiveBuffersUsageGauge.calculateUsedBuffers(inputGate);
	}

	@Override
	public int calculateTotalBuffers(SingleInputGate inputGate) {
		return floatingBuffersUsageGauge.calculateTotalBuffers(inputGate) + exclusiveBuffersUsageGauge.calculateTotalBuffers(inputGate);
	}
}
